This invention is directed to an epoxy application apparatus which includes an epoxy pot and a transfer tool to pick up epoxy from the pot and dispense it to the substrate.
Because of the inherent nature of the device and due to the cost of semiconductor material, semiconductor devices are of minimum size. They must be mounted so that connections can be made thereto. In one common mounting, a semiconductor chip is mounted on a frame which is handled as interconnected units along a strip. Each frame carries its semiconductor chip and each chip is supported by the frame and is electrically connected to the dual inline connectors of the frame. A common mounting method is the employment of a gold alloy so that the chip is brazed by this alloy onto its support. Other methods of mounting include low temperature glass and low temperature ceramic bonding, both of which require heat treatment.
Efforts have been made to attach chips or dies with adhesives such as thermo-setting adhesives, such as epoxy. The problem has been to apply the proper amount of the adhesive at the correct place and with the proper configuration of the deposit. The systems presently available for this type of work are generally pneumatic in nature. In these systems epoxy is loaded into a cylindrical dispenser and is sealed from a gas chamber by means of a movable piston. Pressurized gas is pulsed into the chamber by means of a solenoid valve to result in movement of the piston and the expelling of epoxy from an orifice. Such systems are complex and it is difficult to achieve and maintain the proper flow. Of course, there is continuous bleeding of the epoxy from the orifice, even in the absence of pressure discharging, and the result is deposits of poor shape and irregular size.